Lamp fixture



Sept. 8, 1925.

JNSULA TION A. J. THOMPSON LAMP FIXTURE Filed July 6, 1920 INSULATION 2hun-Shut 1 mar Sept. s, 1925. 1,552,654

A. J. THOMPSON LAMP FIXTURE Filed July 6, 1920 2 Stunt-She 2 .INSULATIOA/ Patented Sept. 8, 1925.

ALLISON J. THOMPSON, or CLEVELAND, OHIO.

LAMP rrx'runn.

Application filed July 6, 1920. Serial- No. 39 1;341.

To all whom it may concern:

Be it known that I, ALLIsoN J. THoMrsoN, a citizen of the United States,residing at Cleveland, in the count-y of Cuyahoga and t-ate of Ohio,have invented certain new and useful Improvements in Lamp Fixtures, ofwhich the following is a specification.

This invention relates to the class of illumination and more especiallyto lamp hangers.

. The type of device to which my invention relates comprises in ageneral way a main hangermember which is fixedly supported in anelevated position and a lamp hanger member which is detachably locked tothe upper or main hanger member so that the lower member can be releasedand lowered by means of a cable for the purpose of inspection, cleaningthe reflector, and renewal of the parts. The improvements in the presentinvention relate particularly to the structure and'arrangement of themechanism for locking the two hanger members together; to the structureand arrangement of the contact membersfor closing the circuit to thelamp when the hanger members are locked together, and to the outletconnection for the lamp.

Fig. 1 partly in full view and partly in section; Fig. 1 is a partialsectional View on the line 1 1" of Fig. 1; Fig. 2 is a side view partlyin full view and partly in section; Fig. 3 is a detailview of the latchmechanism; Fig. 4: is an inverted plan View of one of the female contactmembers; Fig. 5 shows in elevation one of the male contact members; andFig. (5 shows the supporting attachment when an arc lanipis used.

The sheave housing 1, provided with brackets 2 and 3, has pivotedtherewithin the sheave 4. which is mounted upon the pin 5, the outerends of which carry the insulators 6 and 7. The cable 8 enters thehousing 1 through the throatt) andpasses about the sheave in a Wellknown manner. l lai'iges12 on housing 1 are attached to the canopy 11 bymeans of the screws 10.

. The mechanism enclosed in the canopy 11 will now be described. Thesame screws which secure the canopy to the flanges 12 of the sheavehousing serve also to secure in position within the main hanger memberthe tubular guide 13 which is slotted through its full length asindicated at 14. The lower end of the guide 13 is formed with a cam is afront view of my invention face as indicated at 15 forthe purpose ofrotating the lamp hanger member so as to properly align the lowercontacts with the upper contacts. Tubular guide 13 is provided withflange portions 16 and 17 along the margins of the longitudinal slot 141and these-flanges are provided with notches as indicated at 18 for apurpose to be later pointed out. As will be noted from the drawings theflanges 16 and 17 taper in their depth toward their upper ends and havetheir lower endscurved so as to merge into the curvature of the camportion 15. Circular ribs 13 and 13 on the inner face of the tubularguide 13 afford bearing surfaces for the latch stem carried by the lamphanger member, as will later appear. The top'of the canopy is providedwith an aperture registering with the opening through the tubular guide13. As will be seen from the drawings, this aperture is of a key holeform which conforms in a general way to a cross section through thetubular guide 13 in a plane near the upper end thereof. This key holeaperture allows the upper end of the latch stem carried by the lamphanger to pass through the top of the canopy.

Duplicate female contact members are supported within the canopy 11 andareattached to the top wall thereof. These contact members 19 and 20 arearranged on op posite sides of the tubular guide 13, and since they areof the same construction, a description of one of these members willsuiiice. A block of porcelain or other suit able insulating material issecured to the canopy by any suitable means, as for instance bolts 22and 23 which extend through the ears 24 and 25. The female contact,which may be formed of brass, copper or other suitable material, isflared outwardly and has a concave spherical contact surface as shown inthedrawings. This contact is secured to the block 21 by means of thescrew bolt 28, washers 29 and 30 of conductive ma terial being providedfor the clamping of the lead wire. The lead wire is received through thecut-away portion provided in the depending flange 26. Sealingwax orotherinsulating plastic material fills the space around the nut end ofthe screw bolt 28 as clearly indicated in Fig. 1. Insulating bushings 31are provided for leading in the wires through the wall of the canopy 11.The depending flange 26 increases the insulation between the point wherethe lead wire attached to the contact and the nuts on bolts 22 and 23,and thus the possibility of the current jumping between thesetwo pointsis minimized by. the flange 26.

The lamp hanger member, which. carries the lamp and reflector, carriesalso contacts for engagement with the contacts carried by the mainhanger member. Upon raising the lamp hanger member, the upper part offin 1:1 on the latch stem engages the cam surface 15 and thereby causesthe lamp hanger member to rotate until the fin is in alignment with theslotl land the lower contacts are brought into alignment with the uppercontacts. The contacts are then brought into engagement and the twohanger members are brought into locked relation. Then upon unlocking thetwo hanger memhere, the lamp hanger is lowered and the contacts areseparated.

The lamp hanger member is provided with a latch stem 1a: which passes upthrough the tubular guide 13, the latch dog 4-2 being pivotally mountedupon the fin ed on the latch stem l t. The lower portion of the fin llhas greater radial extent with respect to the latch stein than the upperportion thereof. Thisarrangement is for the purpose of allowing properradial movement of the dog in locking and unlocking the same, as will beseen from Fig. 1. The dog is of a clevis form and is pivoted upon theenlarged portion of the fin 4C1 by means of the pin L3. The dotted linesrepresented at n indicate the point where the full or base portion ofthe latch stops, or, in other words, indicates the extent to which thelatch can swing upwardly before striking the fin ll. This arrangementconstitutes a stop for the dog in its upward swinging movement. The fin4-1 is located with respectto the notches 18 so that the tail of the dog12 will swing into locking engagement therewith.

The latch dog 42 is shaped eccentrically with respect to its pivotalpoint, and that portion indicated at 42 which is on the side of thepivot point away from the tail of the dog, is suiliciently heavy tocause a quick swinging of the dog about its pivot in acounter-clock-wise direction upon release thereof, as veiewd in Figs. 2and 3, as will be later explained. The tail'of the dog has a face 4-2which engages the upper edge of the notches upon raising the lat-ch stemin the unlocking operation; while the face T2 of the dog is adapted toengage the lower edge of the notches as the latch stem is lowered. Theface 42 is so formed that there is no danger of the dog sticking on thelower edge of the notches or swinging into the notches during then'ioven'ient. of this face down past the lower edge thereof. It is alsonoted that the tail of the dog, when in locked position, extends in anapproximately horizontal direction and abuts against the bottom 18 ofthe notches and'the lower face of the tail of the dog engages the lowerside 18" of the notches. That is to say, one component of, forceisdirected in a horizontal plane against the side of the tubular guideand another component of force is directed in a vertical directionagainst the lower part of the flanges 16 and 17. The first namedcomponent of force efi'ects a decided binding action between the latchstem and the tubular guide in a substantially horizontal plane. Both ofthese components of force vary directly. as the weight suspended fromthe latch stem. It is further pointed out that the binding actionreferred to can be increased by placing the pivotal point of the dogfarther away from the tubular guide, or, in other words, by increasingthe degree of eccentricity of the dog to which reference was made above.The binding act-ion re ferred to can also be increased by locating thenotches 18 midway of the bearing ribs 13 and 13".

The cable 8 extends through the latch stem i l and its knotted lower endengages.

the apertured disk 39 which in turn engages across the lower end of theopeningthrough the latch stem. In this way a means'is provided forraising the lamp hanger member, although other suitable means might beadapted for effecting engagement between the cable and the lamp hangermember. The lower enlarged end'poition of the latch stem is surroundedby coil spring 3 1:, the ends of which abut the flange 36 on the end ofthe latch stem andthe inwardly projecting flanges on the upper part ofthe cylindrr cal housing 32, one of which last named flanges is shown insection at The other flange 33 is ofth'e same width as flange Theflanges 33 and 33 are forced by the spring 3 1 into abutting engagementwith the lugs 35 which project radially from the latch stem. The flanges33 and 33 are provided with recesses 37 to receive the lower portions 38of the lugs 35 so as to prevent axial turning of the latch stem withinthe housing The purpose of the spring 3% is to permit upward movement ofthe latch stem against the tension thereof independently of the housing32 and the contact members carried thereby, as will now be more fullyset forth.

The lower end of the latch stein has screw threaded engagement with theoutlet connector member 60 through which extend the wires to the lampwhich is attached to the screw threads 61, in case an incandescent lampis used. As will be seen from Fig. 1, the wires from the two sidesextend through the diametrically opposed sides of the out let, asindicated at 62 and (52, and thence through the neck 63 to the lampsocket. In case an arc lamp should be used, the plug attachment shown inFig. 6 is screwed into Ill) the lower end of the latch stem and the arelamp is supported from the loop 65.

The housing member 82 is provided with" diametrically opposed webs l5and 46 extending upwardly therefrom and terminating in the horizontallydisposed ears i? 48. These ears are apertured and receive floatingcontact members which are duplicates and only one of which willtherefore be described. The lower insulating member is provided with aboss 49 which extends upwardly through the aperture in the ear 4:8 andis formed on-its lower side with depending skirt or flange 50 which hasa cutaway portion 51 to accommodate the reception of the lamp wire, asclearly shown in Figs. 1 and i. The flange 50 minimizes the possibilityof the current jumping across from the end of the lamp wire to the metalwall of the housing 32 and in this wa increases the insulation. Asillustrated in Fig. 4, the depending flange 50 is curved throughout aportion thereof to conform to the curvature of the housing member 32 andis spaced therefrom to allow movement of the insulating member in ahorizontal plane. An upper insulating member 52 engages the boss 49 onthe lower insulating member, a cushion washer of paper or. otherinsulating material being provided between the faces of these twoinsulating members for the purpose of compensating for expansion andcontraction of the parts. These insulating members are provided withregistering apertures for the screw bolt 5-1 which extends therethrough.The inner portion of wall 50 prevents turning of the nut of the screwbolt and hence facilitates assembly of the parts A sleeve 55 ofinsulating material surrounds the screw bolts lVashers 55 and 56 ofconductive material are clamped against the under face of the lowerinsulating member 50 so to provide a binding post for the lamp wire. Acontact 57 is clamped in position upon the upper face ofthe insulatingmember 52 by means of the screw bolt 54; and a cushion washer ofsuitable insulating material is provided to compensate for expansion andcontraction of the parts. The contact 5? is cup shaped with its engagingcontact surface formed as a segment of a sphere so as to all-owuniversal engagement with the female contact carried by, the upperhanger member. As clearly indicated in Fig. l, the contact 57 ishollowed out so as to allow insertion of the screw bolt there through.The tapered boss 4-9 is of greater extent than the thickness of the ear%8 and has play in a horizontal plane in the aperture of ear 4: Thus thecontacts carried by the lamp hanger member are capable of movement bothin vertical and horizontal planes and are therefore said to be yieldingor floating. I

In assembling the parts, for use with an incandescent lamp, the wiresfrom the lamp are passed up through the neck 63 and are allowed toproject straight up through the open upper end thereof. The lower end ofthe connector is then screwed into the lamp socket and the upper ends ofthe wires are next passed down through the side extensions 62 and 6 Thenthe connector incinber carrying the lamp screwed into the lower end ofthe lamp hanger member and the upper ends of the wires are attached tothe binding posts. Thus with this ar-,

this way brin the contacts into en agement under firm tBllSlOll. Furtherraising of the latch causes the tail of the dog to ride up over theflanges l6 and 1?, to a point opposite or above the notches l8,whereupon it will swing into engagement therewith upon slowly loweringthe latch stem. vVhen it is desired to disengage the two hangerHlG-llllOEl'S the latch stem is raised against the tension of thespring, whereupon the tail of the dog rides up over the upper edges ofthe notches 18. Then by quickly releasing the cable, the dog is carrieddownwardly past the notches before its tail has ill'llB to swing intothe notches. The lamp hanger men'iber is then wholly disengaged from themain hanger member and can be lowered tor purposes of? inspecting orrenewing the parts carried thereby and also for cleaning the lampreflector.

Thus it will be seen that the. lamp member can be readily lowered tocleaning of the reflector as well as inspection and renewal oi? all ofthe parts, includ ing the lamp. the latch dog and the floating contacts.The location of the latch dog and floating cont-acts upon the lamphanger member constitutes a very important advantage in connection withmy present de vice. Furthermore, my particular latch mechanism has adecidedly positive action andproduces a very sill-active binding orpinching engagement between the latch stem and the tubular do when theseparts are locked together. The particular structure and arrangement ofmy insulating means for both the uppe and lower contacts constitutesanother advantage of this invention hanger permit as also the particularfloating arrangement of the male contacts which insures properengagement thereof with the female contacts. A further advantage residesin the fact that I avoid the objectionable twisting of the wires inattaching a lamp to the lamp hanger member.

\Vhat I claim is:

1. In a lamp hanger, a main hanger member, a lamp hanger member,latching mechanism for locking said members together, fixed contactscarried by the main hanger member and indiyidually floating contactscarried by the lamp hanger member, each cl said floating contactscomprising a sectional insulator and a contact member, and a singlemeans for securing together said insulator sections and the contactmember.

2. In a lamp hang r, a main hanger member, a lamp hanger member,latching mechanism for locking said members together fixed contactscarried by the main hanger member, individually i ioating contactmembers carried by the lamp hanger member and co-operatingwith the linedcontacts of the main hanger member, aperiured supports :l'or saidfloating contact members, each of said floating contact men'iberscomprising an insulating means loosely mounted in said aperture, saidinsulating means having vertical and lateral movement in said aperture,and a, contact carried by said insulating means.

In a lamp hanger, a main hai'iger incinber, a lamp hanger member,latching mechanism for locking said members together, fixed contactscarried by the main hanger member and having concave sphericalcontacting surfaces, said concave surfaces being spaced from the mainhanger member in dividually floating contact members carried by the lamphanger member, said last named hollow contact members having convexspherical contact "faces for co-operation with said fixed contacts,bolts securing said contact members to said lamp hanger member andarranged with their heads seated within said hollow contact members,

a. In a lamp hanger, a main hanger memher, a lamp hanger member,latching mechanism for locking said members together, fixed contactscarried by the main hanger member, individually floating contact memberscarried by the lamp hanger member and co-operating with the linedcontacts of the main hanger member, apertured supports for said floatingcontact members, each of said floating contact members con'iprising asectional insulator extending through said apertured support andcarrying a contact, and a single means tor clamping together saidinsulator sections and said contact,

In a lamp hanger, a main hanger member of non-insulating material, alamp hanger member, separate insulating blocks carried by the mainhanger member, contacts mounted upon said blocks and approximately inthe main axis thereof, means for attaching lead wires to said contacts,said blocks being provided with flanges of in sulating materialdepending below the points of attachment of the lead wires to preventjui'nping of the current, said depending flanges having cut-awayportions to facilitate connection of the lead wires to said contactmei'nbers, and contacts carried by said lamp hanger member forco-operation with said first named contacts.

6. In a lamp hanger, a mainhanger menr her, a lamp hanger member,latching mechanism for locking said members together, fixed contactscarried by the main hanger men'iber, individually floating contactmembers carried by the lamp hanger member and ce-operating with thefixed contacts of the main hanger member, apertured supports for saidfloating contacts, each of said floating contact members comprising asectional insulator extending through'said apertured support andprovided with a depending ange, a contact carried by said insulator, anda single means for clamping together said insulator sections andsaidcontact, said means including a screw bolt and nut, said dependingflange extending in suliiciently close proximity to raid nut to preventturning oat same on said bolt.

7. In a lamp hanger, a main hanger memher, a lamp hanger member,insulating blocks for said main hanger member, means for securing saidblocks to said main hanger member, said means including nuts and screwbolts, said screw bolts extending through said'blocks, said blocks beingprovided with means to engage said nuts and thereby prevent the samefrom turning upon said bolts.

8. In a lamp hanger, a main hanger member, a lamp hanger member, aslotted guide tube carried by one of said members, a latch stem carriedby said other member and adapted to be received by said slotted tube, alatch dog carried by said stem and means provided upon the outside ofsaid slotted tube tor locking engagen'ient with said latch dog.

9. In a lamp hanger, a main hanger member, a lamp hanger member,co-operating contacts carried by said members, a slotted guide tubecarried by said main hanger member, a latch stem carried by said lamphanger member and adapted to be received by said slotted tube, a latchdog carried by said stem and means provided upon the outside oii saidslotted tube "for locking engagement with said latch dog.

10. In lamp hanger, a main hanger member, a lamp hanger men'iber,co'operating contacts carried by said members, a slotted guide tubecarried by said main hanger member, a latch stem carried'by said lamphanger member and being provided with a fin extending longitudinallythereof, said slotted tube being adapted to receive said stem with itsfin, a latch dog pivotet upon the outside of said fin, engaging meansprovided upon said tube for locking engagement with said latch dog andmeans provided upon said guide tube in the path of said latch dog as itis moved in an upward direction for causing said dog to swing out andclear said engaging means downward movement thereof in the unlatchingoperation.

11. In a lamp hanger, a main hanger member, a lamp hanger member,co-operating contacts carried by said members, a slotted guide tubecarried by ,said main hanger member, a latch stem carried by said lamphanger member and being provided with a fin extending longitudinallythere of, said slotted tube being adapted to receive said latch stemwith its fin, a latch dog pivoted upon said fin, said guide tube beingprovided upon the outside thereof with a recess adapted to receive saidlatch dog in looking engagement, the upper edge of said recess beingadapted to engage said dog in its upward movement and to cause it toswing out and clear said recess on downward movement thereof in theunlatching operation.

12. In a lamp hanger, a main hanger member, a lamp hanger member,co-operating contacts carried by said members, a slotted guide tubecarried by said main hanger member, a latch stem carried by said lamphanger member and adapted to be received by said slotted tube, alatch.dog carried by said latch stem, means provided upon the outside of saidslotted tube for locking engagement with said latch dog, and means forcausing disengagement of said latch upon upward movement of said latchstem, thereby allowing said lamp hanger member to be lowered away fromsaid main hanger member.

13. In a lamp hanger, a main hanger member, a lamp hanger member,co-operating contacts carried by said members, a slotted guide tubecarried by said main hanger member, a latch stem carried by said lamphanger member and being provided with a fin extending longitudinallythereof, said slotted tube being adapted to receive said latch stem withits fin, a latch pivoted upon the outside of said fin, dog receivingmeans provided upon said tube for locking engagement with said latch,and means provided upon said guide tube in the path of said latch as itis moved in an upward direction for causing said dog to swing out a d la s id d re vi g m ans on downward movement thereof in the unlatchmgoperation, the tail of said latch dog being eccentrically arranged withrespect to the pivot point thereof and extending in an approximatelyhorizontal direction when in locked position, whereby there is caused aclamping of said dog against the side of said guide tube and a bindingor pinching action through an approximately horizontal plane is effectedbetween the guide tube and the latch stem.

14:. In a lamp hanger, a main hanger member, a lamp hanger member,co-operating contacts carried by said members, a slotted guide tubecarried by said main hanger member, a latch stem carried by said lamphanger member and being provided with a fin extending longitudinallythereof, said slotted tube being adapted to receive said latch stem withits fin, said guide tube being provided with bearing ribs upon its innerface and with a notch located between said ribs to receive said dog, thetail of said dog being eccentrically arranged with respect to its pivotpoint and extending in an approximately horizontal direction when inlocked position, whereby there is caused a clamping of said dog againstthe side of said guide tube and a binding or pinching action through anapproximately horizontal plane is effected between the latch stem andthe bearing ribs on said guide tube.

15. In a lamp hanger, a main hanger member, a lamp hanger member, aslotted guide tube carried by one of said unembers, a latch stem carriedby said other member and adapted to be received by said slotted tube, alatch dog pivotally mounted upon said latch stem and lying outside ofsaid tube and being weighted at the side of the pivot point away fromthe tail of the dog and means provided upon the outside of said slottedtube for locking engagement with the tail of said latch dog.

16. In a lamp hanger, main hanger member, a lamp hanger member,co-operating contacts carried by said members, a slotted guide tubecarried by said main hanger member, a latch stem carried by said lamphanger member and being provided with a fin extending longitudinallythereof, said slotted tube being adapted to receive said latch stem withits fin, a latch pivoted upon said fin, said guide tube being providedon the outside thereof with a recess adapted to receive said latch dogin looking engagement, the tail of said latch dog having a face forengagement with the upper edge of said recess to cause said dog to swingout of said recess, and the tail of said dog hav ing also a face whichis adapted to ride down over the lower edge of said recess, up onlowering of said latch stem, so that said dog will clear said recess.

17, In a lamp hanger, a sectional insulating support for an electricContact comprising an insulating member having a recess in one facethereof, a second insulator member having a boss for engagement in saidrecess, a screw boltextending through said members and adapted to securealso an electric contact upon said first named insulator member, saidboss being of sufiicient extent to provide space between the adjacentfaces of said members for the engagement with an apertured support,means upon the end of the screw bolt tor attaching an electric wire,said second named insulator member being; prov'ded with a flange ofinsulating material extending past the point of attachment of the Wireand said flange having a cutaway portion to facilitate attachment of theWire.

In testimony whereof I affix my signature.

ALLISON J. THOMPSON.

